Keyed insulating board



c. A. ROLFE KEYED INSULATING BOARD vMay 5,1925.

Filed Aug. 17, 1921 nwf;

Patented VMay 5A, 1925i l UNITED STATES 'CHARLES A. Roni-in, or sT. PAUL, MINNESOTA.

, r f Knynn INSULATING BOARD.

Application .1ed Augiistl?, 1921. Serial No. 493,153f

`To all whom t may concern! Be it known that I, CHARLES A. Bonini,

a `citizen of the United States, and a resi- `dent of St. Paul, in the county of Ramsey and State of Minnesota, haveinvented certain new yand yuseful yImprovements in Keyed Insulating Boards, of Which the following is a specification.

One object of my inventionis to provide in an article of thekind described improved means fory keying plaster thereto.

Another object is to provide in an article .of the kind described a face that Will have a maximumstrength for the material used 'and a back that Will have maximum insulating qualities forthe material used.

With these and incidental objects invieiv, the invention *consists of certain novel features of construction and vcombination of parts, they essential elements 'of which` are hereinafter described with' reference to the drawing, Which accompanies and forms a part of this specification.

In .the drawing Fig. l is a side eleva-v tion'of one embodiment of my invention; Fig.` 2 is a section taken on the line 2-2, Img. l; Fig. 3l is a section taken on the line 343, Fig. l; Fig. 4 is a perspective view of the board shown in Iiig. l and Fig. 5 is a conventional representation of one means by which the boai'd may be manufactured. n

As shown in Fig. 5 the back board l is formed by any suitable Wet process and is` brought to the rolls 2 While it is still moist.

The face board 3 is likewise 'formed by any suitable Wet process and has formed therein the dovetailed keys i during the process of making the sheet. y

The face sheet 3 is preferably` made of a firmer and stronger texture than the back sheet l, which is preferably somewhat loose in texture and has a high insulating rvalue and the tivo` sheets are joined together by pressure of the rollers 2 so as to combine into a composite sheet 5, Fig. 5.

The dovetail keys 3 are similar to those described in my copending application of even date, entitled Keyed board, and. the substantialr difference between the t-Wo inventions is' that while in the other application aforesaid, the board is formed of tWo individual boards that are `joined together ina suitable manner after they are completely formed, in this invention the two portions, face and back,

insulating are `joined during the process of manufacture so the result is a board, the face of which has great strength and the back of. ,ivhich has high insulating qualities.

"A board madevin thisstyle hasgreat mechanical strength on account of the nature of the face portion of the board, which also has some insulating qualities, and has dhigh insulating qualities on account of the backportion or the board, which is formed particularly with reference to yobtaining the `highest insulating qualities.. i

Such a. board is extremely cheap yto inanufacturerand to mount on a studding and at the same time it gives great mechanical strength and has high insulating qualities.

lllliile I have described my invention and illustrated it in yone particular design, I do not Wish it understood that I limit myself to this construction, as it is evident that theapplication of the invention may `be varied in many Ways `Within the scope of the following claims:

Claims:

l. As an article of manufacture an insulating hoard having thefront portion thereof of strong texture and having in corporated therein plaster keying means and having the integral back portion there-` of of comparatively great thickness' and of loose texture and high insulatingqual` ities.

2. 'As an article of manufacture an insulating board having vthe face thereof` to a considerable depth formed of one texture and the integral back thereof of a different texture having high insulating qualities and i of comparatively great thickness.

8. As an yarticle of manufacture an in-` sulating boardhaving the face thereof of a lirni, strong texture Shaped keys therein the edges of which` incline toward each otliei`toward the top CHARLES A. nomic. -l

and having dovetail 

